C-peptide (Serum, Post-Meal)
This test measures C-peptide, a natural byproduct of insulin production, to help assess how your pancreas is functioning after you eat.
["C-peptide helps evaluate insulin production and diabetes management after meals."]
Key facts at a glance
- LOINC
- 95082-4
- Short code
- C peptide 1h p meal SerPl-mCnc
- Synonyms
- C peptide 1h p meal SerPl-mCnc
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test if they suspect diabetes, poor insulin production, or other metabolic conditions. It can also help monitor how well insulin is working in people with diabetes who take insulin therapy or have prediabetes.
What Does the Test Measure?
C-peptide is released along with insulin when your pancreas produces it. Unlike insulin, which is broken down quickly in the bloodstream, C-peptide remains stable and can be measured in your serum after a meal.
How Is the Test Performed?
A blood sample is taken from a vein, usually in your arm, after you have eaten a standard meal. The sample is then sent to a lab for analysis using a high-performance liquid chromatography (HPLC) method.
What Do the Results Mean?
Results help determine if your pancreas is producing enough insulin independently of external sources (like insulin injections). Low levels may indicate insulin deficiency, while normal or high levels can help rule out other conditions.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: This test is particularly useful for diagnosing type 1 diabetes, distinguishing between insulin-dependent and insulin-independent diabetes, and assessing the effectiveness of insulin therapy in people with type 2 diabetes or other metabolic disorders.
Short name
C-peptide after eating
Frequently asked questions
What happens if my C-peptide levels are low?
Can I eat or drink anything before the test?
How long does it take to get the results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy